Laparoscopic surgery, also called minimally or less invasive surgery (MIS or LIS) or keyhole surgery is a modern surgical technique in which operations in the body are performed through small incisions as compared to the larger incisions needed in traditional surgical procedures. Gas such as carbon dioxide is delivered, via an insufflator, into a body cavity such as the abdomen leading to the formation of a pneumoperitoneum, thereby providing sufficient space for the surgeon to operate. The insufflator maintains the pneumoperitoneum and acts to renew the gas when leaks occur.
Gas, such as, for example, carbon dioxide, that is used for insufflation is both cold and dry and it is not surprising therefore those patients undergoing laparoscopic procedures often suffer a significant drop in core body temperature, which can result in considerable post-surgical pain and significant complications, such as cardiac stress, immunological and clotting problems, for the patient. By using standard thermo physical principles it has been shown that the major cause of patient heat loss is due to evaporation from the body acting to humidify the large volumes of dry insufflated gas at ATPD (Ambient Temperature Pressure Dry) passing into the body which is at BTPS (Body Temperature Pressure Saturated). If such heat loss could be minimized, post-operative pain and the significant side effects suffered by the patient could be considerably alleviated.
Various attempts have been made to condition insufflation gas by heating, humidifying, and/or filtering the gas. However, in general, known insufflation gas-conditioning systems suffer from one or more disadvantages including complexity of construction involving expensive monitoring devices, inaccurate control, and/or difficulties in using them in a controlled working environment.
Some systems employ heat moisture exchangers (HME). These operate directly in the flow path of the insufflation gas and are therefore inherently susceptible to affecting pressure or flow, dependent upon their level of saturation and condition. Other systems require manual intervention to respond to patients' needs by the adding of moisture. Other devices require the cumbersome procedure of passing gas over and through non-heated or heated liquid containers. Such devices present the major drawback of impeding pressure measurement in the insufflation cavity.
Systems using conventional jet nebulizers or nebulization catheters exhibit one or more of the following disadvantages: impaction of larger particles; fogging in the body cavity thus reducing the surgeon's visibility; and interference with insufflator settings increasing flow/pressure in the system.
The present invention is directed towards providing an insufflation method and apparatus.
Flow of aerosol through long lengths of tubing may lead to increased rainout and loss of suspended aerosol delivered to the pneumoperitoneum. This impacts both effectiveness of the treatment and the time required to deliver any given medication volume.
Standard connections for inflow gas at a Trocar housing tend to be small diameter with sharp 90° changes in flow direction. This may lead to increased rainout and loss of suspended aerosol delivered to the pneumoperitoneum.
Access to the control mechanism for the aerosol generator is generally remote from the patient. This may inconvenience the surgeon where immediate changes in aerosol delivery are required during the course of a procedure.
Delivery of aerosol into the pneumoperitoneum is generally completely dependent on the flow at insufflator. Where the insufflator is providing low flow, aerosol may not be carried into the pneumoperitoneum.
Positioning the aerosol generating element on the tubing circuit between the insufflator and the Trocar presents challenges such are location, need for supporting brackets, and potential to obscure displays on important equipment.